While harmful alcohol use among young adults bears many deleterious consequences on its own, drinking often is accompanied by the concomitant use of other substances.  Cannabis is perhaps the most common recreational substance that is concurrently used with alcohol (sans nicotine), and its effects manifest in a variety of physiological and psychological manners.  Additionally, prescription stimulant use may simultaneously occur during drinking episodes, representing an understudied behavior pattern in college student populations.  This study aims to identify potential interactions between alcohol-related cognitions and the co-use of alcohol with cannabis, and alcohol with prescription stimulant drugs using the Prototype Willingness Model as a framework.

The study’s sample was comprised of 1062 young adults who previously participated in a survey examining interactions between alcohol use and risky sexual behavior (N=1062, mean age =19.7 yrs., 54.5% female).  Relevant eligibility criteria included having used alcohol at least once in the prior three months.  The participants completed a survey which included a battery of assessments and measures of the following characteristics: demographics, alcohol use, cannabis use, prescription stimulant use, frequency of concurrent use of the aforementioned substances, perceived descriptive drinking norms (via Drinking Norms Rating Form), prototype similarities (e.g. “how similar are you to the average x-aged female in terms of drinking frequency?”), perceived vulnerability of consequences, and willingness to drink.  The data was analyzed using ordered logistic regression modelling. 

Results of the analysis found in the prior three months about 85% of the sample reported co-use of alcohol and cannabis, 24% reported co-use of alcohol and prescription stimulants, and 25.3% reported simultaneous use of all three listed substances.  Significantly higher odds of alcohol-cannabis co-use were found specifically for white, male, college students, in addition to having elevated willingness to drink and increased descriptive alcohol norms.  Similarly, willingness to drink and descriptive norms predicted alcohol-prescription stimulant co-use.  Prototype similarities and vulnerability perceptions were not found to interact with the variables of interest in the model.

Takeaway: when examining the co-use of different substances in young adult populations, this study suggests the best general predictors of the behavior may be found in and individuals’ willingness to drink and perceived descriptive norms.  Additional research is needed to determine the relationships of these variables from a demographic perspective. 

Litt DM, Lowery A, LoParco C, Lewis MA. Alcohol-related cognitions: Implications for concurrent alcohol and marijuana use and concurrent alcohol and prescription stimulant misuse among young adults. Addictive Behaviors. 2021;119:106946. doi:10.1016/j.addbeh.2021.106946